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Record W6986973758

Scale-invariance and patchiness in the plankton

2001· dissertation· en· W6986973758 on OpenAlexaboutno aff

Bibliographic record

VenueThe Atrium (University of Guelph) · 2001
Typedissertation
Languageen
FieldEarth and Planetary Sciences
TopicMarine and coastal ecosystems
Canadian institutionsnot available
Fundersnot available
KeywordsZooplanktonPhytoplanktonPlanktonMultifractal systemTransectEstuaryTurbulence
DOInot available

Abstract

fetched live from OpenAlex

An 'in-situ' oceanographic CTD probe linked to an Optical Plankton Counter was used to produce a collection of transects in the nearshore region of the Gulf of St. Lawrence estuary near Rimouski, Quebec. Gap relationships at the millimeter-meter scale, using a Distance to Next Encounter (DNE) indicated that zooplankton were significantly aggregated into patches and randomly distributed within patches and new statistics were used to describe 'in-situ' patchiness. Zooplankton distributions were compared with the CTD data (salinity, oxygen, temperature, optical transitivity, and phytoplankton as fluorescence). Spectral analyses indicated that the plankton spectra (variance as a function of frequency scale) were different from a "passive scaler" (temperature), which had only one scaling region with slope [beta]~5/3 (Kolmogorov turbulent value). Zooplankton had 2 scaling regions: >300m with [beta]~5/3 and <300m with a [beta]~0. Phytoplankton had 3 scaling regions: >300m and <40m which had [beta]~5/3 with an intermediate scale (40-300m) with [beta]~0. Multifractal analysis indicated both zooplankton and phytoplankton were extremely multifractal ("spiky") with [alpha]~1.8-1.9, but with low C1~0.05 indicating mean values were common. A simple model is presented involving growth and turbulence to account for the large-scale, and grazing and turbulence (predator-prey zooplankton/phytoplankton interactions) to account for the small-scale (particularly H, related to [beta]). Depending on a dimensionless grazing constant, small scales are dominated by turbulent grazing (Gr > 1) or passive-scalar turbulence (Gr < 1). Within the grazing regime, H = -1/3, zooplankton preferentially graze the high concentration phytoplankton patches. Multifractal analysis of zooplankton indicated a strong similarity with phytoplankton multifractal parameters for scales 300-40 m, but phytoplankton were otherwise passive-scalers, indicating zooplankton modify the distribution of phytoplankton at these scales. The multifractal parameters: [alpha] and C1 provide a full description of a complex field to high statistical moments. Ranges of realistic patchy food fields were simulated using the multifractal process. Capture success of planktonic copepods was then investigated in an individual-based model. Average capture rates declined with increased patchiness, but individual capture rates were higher at increased patchiness, then becoming increasingly log-normal as most individuals captured no food.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.020
Threshold uncertainty score0.041

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.000
Science and technology studies0.0000.001
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.009
GPT teacher head0.188
Teacher spread0.178 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2001
Admission routes1
Has abstractyes

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